1. Field of the Invention
The present invention relates to a scan format converter for converting a video format, and in particular, to a method for making look-up tables of variables and interpolation values necessary for bi-sigmoid interpolation and a scan format converter for converting an input video format to another video format by using the look-up tables.
2. Description of the Related Art
With the popularization of personal computers (PCs), there are demands for a personal computer capable of displaying a video output thereof through a display unit of a home television or a projection television. In practice, however, since there is a discrepancy in the number of the scanning lines between the television set and the personal computer, it is impossible to output various formats (e.g., SVGA, XGA, VGA, etc) input from the personal computer to the display unit, as they are. Accordingly, it is necessary to convert the input video formats in conformity with the properties of the display unit. A scan format converter has been developed for that purpose.
However, the conventional scan format converter, utilizing bi-linear interpolation or zero-order interpolation, cannot display the high quality image of the personal computer to the display unit of the television set or the projection television.